Seiko Cal. 5640 - 198

This Spring Drive model from 1976 features a 44mm Titanium case. Powered by the 5640 caliber with 18j jewels beating at 21,600 bph, it delivers a 63 hours power reserve. [seikata-wm-20a6ac07186f]

Also known as: Helmet, UFO

Specifications

Movement

Spring Drive

Case Material

Titanium

Case Width

44mm

Case Thickness

9.1mm

Lug Width

18mm

Crystal

Sapphire

Bezel

Inner Rotating

Water Resistance

40m

Dial Color

Cream

Jewels

18j

Frequency

21,600 bph

Power Reserve

63 hours

Year

1976

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